Software Engineering Institute

The Acer AcerCtrls.APlunch ActiveX control is provided by acerctrl.ocx. It contains a method called Run(), which takes two parameters: Drive and FileName. Although the control is not inherently marked as safe for scripting via the IObjectSafety interface, it may be distributed with the appropriate Implemented Categories registry key to make it safe for scripting. This means that a web page in Internet Explorer can call the Run() method of the control.

Note that this vulnerability is similar to but not the same issue as VU#221700. This control has different parameters and uses a different CLSID that is not included in the killbits provided with Microsoft Security Bulletin MS07-027.

By convincing a victim to view an HTML document (web page, HTML email, or email attachment), an attacker could run arbitrary commands with the privileges of the user running IE.

We are currently unaware of a practical solution to this problem. Please consider the following workarounds:

Disable the Acer AcerCtrls.APlunch ActiveX control in Internet Explorer

The Acer AcerCtrls.APlunch ActiveX control can be disabled in Internet Explorer by setting the kill bit for the following CLSID:

{3895DD35-7573-11D2-8FED-00606730D3AA}
More information about how to set the kill bit is available in Microsoft Support Document 240797. Alternatively, the following text can be saved as a .REG file and imported to set the kill bit for this control:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\ActiveX Compatibility\{3895DD35-7573-11D2-8FED-00606730D3AA}]
"Compatibility Flags"=dword:00000400
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Internet Explorer\ActiveX Compatibility\{3895DD35-7573-11D2-8FED-00606730D3AA}]
"Compatibility Flags"=dword:00000400
Disable ActiveX

Disabling ActiveX controls in the Internet Zone (or any zone used by an attacker) appears to prevent exploitation of this and other ActiveX vulnerabilities. Instructions for disabling ActiveX in the Internet Zone can be found in the "Securing Your Web Browser" document.